Investigating the impact of calibration timescales on streamflow simulation, parameter sensitivity and model performance for Indian catchments

ABSTRACT

Hydrological model calibration is a quintessential step in model development, and the time scale of calibration depends on the application. However, the implications of choice of time scale of calibration have not been explored extensively. Here, we evaluate the effect of the time scale of calibration on model sensitivity, best parameter ranges, and predictive uncertainty for three river basins using the Soil and Water Assessment Tool (SWAT) model. Multiple models were set up for three different catchments from southern India. Our results showed that the sensitivity of the parameters, best parameter ranges, and model performance are conditioned on the time scale of calibration. The models calibrated at coarser time scales marginally outperformed the models calibrated at fine time scale in terms of Nash-Sutcliffe efficiency and percentage bias. Transfer of parameters across scales (both from coarse to fine and from fine to coarse) have a general tendency to worsen the model performance in all three catchments, with few exceptions.

KEYWORDS:

• time scale of streamflow calibration
• SWAT model
• sensitivity analysis
• transferability of parameters

Editor A. Castellarin Associate Editor S. M. Pingale

Editor A. Castellarin Associate Editor S. M. Pingale

Acknowledgements

The financial assistance provided by SERB, Government of India, under the Early Career Research Award held by Dr Maheswaran is gratefully acknowledged. AA and BM acknowledge the joint funding support from the University Grant Commission (UGC) and DAAD under the Indo–German Partnership in Higher Education (IGP) framework for the COPREPARE project.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This work was supported by the SERB, Government of India, under the scheme [Early Career Research Award]; University Grants Commission [IGP2020-24/COPREPARe].